138556656 has 140 divisors (see below), whose sum is σ = 460266672. Its totient is φ = 39564288.

The previous prime is 138556651. The next prime is 138556657. The reversal of 138556656 is 656655831.

138556656 is a `hidden beast` number, since 1 + 3 + 85 + 566 + 5 + 6 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138556651) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 80800 + ... + 82496.

Almost surely, 2^138556656 is an apocalyptic number.

138556656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138556656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230133336).

138556656 is an abundant number, since it is smaller than the sum of its proper divisors (321710016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138556656 is an equidigital number, since it uses as much as digits as its factorization.

138556656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1730 (or 1709 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The square root of 138556656 is about 11771.0091326105. The cubic root of 138556656 is about 517.4588247013.

The spelling of 138556656 in words is "one hundred thirty-eight million, five hundred fifty-six thousand, six hundred fifty-six".